Encoders vs. Resolvers

Nidec-Avtron offers both Encoders and Resolvers.

How are incremental encoders different than resolvers?

Output Signal

Encoders produce pulses indicating movement over a short distance; counting these pulses indicates distance (and speed over time) and checking the order of pulses in channel A vs. channel B indicates direction (quadrature).

Resolvers produce a set of sine/cosine waves (analog voltage) indicating absolute position within a single revolution; these signals are typically converted with a resolver interface board to a digital signal.

Input Signal

Encoders are typically powered with simple DC voltage.

Resolvers are "excited" by an AC reference sine wave, typically created with a dedicated resolver power supply; this power supply is typically powered with simple DC voltage.

Location of Electronics

Encoders typically have all their electronics onboard, minimizing interconnections, but limiting operating temperatures.